The oxidizing air pollutants ozone and nitrogen dioxide may exert their toxic action by peroxidation of the unsaturated fatty acids of the lung and other tissues. To test this hypothesis, mice will be fed chemically defined diets known to produce lung lipids having differing rates of peroxidation. Diets will be sufficient or deficient in vitamin E. Various levels of vitamin E, similar to those found in human diets, will be fed to determine if protection against air pollutants is a function of the level of vitamin E or the composition of the lung lipids. The levels of ozone and nitrogen dioxide will be varied to provide differing rates of peroxidation. The effects of diet and oxidant stress upon potential detoxification enzymes will be determined. The effect of air pollution on the turnover of vitamin E in tissues will also be determined. These data will be used to assess the potential changes in the human dietary requirement for vitamin E as the result of air pollution exposure. In addition, these experiments will be formulated to test for putative toxic intermediaries, for a free radical mechanism of action of oxidizing air pollutant intoxication, and for protection against ambient air pollutants by dietary alterations in lipids and vitamin E supplementation. BIBLIOGRAPHIC REFERENCES: D. B. Menzel, J. H. Roycroft, and W. B. Gunter. Ozone Toxicity: Hormonal-Like Products from Ozone Catalyzed Oxidation of Arachidonic Acid. First International Congress of Toxicology, Toronto, Canada, 1977. D. H. Donovan, S. J. Williams, J. M. Charles, and D. B. Menzel. Modification of Mouse Lung Lipids by Dietary Fat and Tocopherol. Fed. Proc. 36, 1158 (1977).